Study on the Relation between Oscillation Frequency of Self-Excited Oscillation Pulsed Water Jet and Self-Excited Pulsed Water Jet Devices

Abstract

Depending on different structure characteristic of nozzle (self-excited oscillation chamber and special boundary condition), the self-excited pulsed water jet can be produced,which can increase the jet pressure and having the cavitation phenomenon. So,it has been applied in oil driven well、mining and building etc.To study the relation among the frequency of the jetting peak pressure,the peak pressure of the plused-jetting and the self-excited pulsed water jet device,based on the theory of fluid network,the mathematical model of the self-excited oscillation pulsed water jet device was established and the dynamic characteristics parameters of the self-excited oscillation pulsed water jet were tested, which shows that the frequency of the self-excited oscillation nozzle depend on the structure parameter and the dynamic state characteristic of the fluid decisive .the frequency of the jetting peak pressure depends on natural frequency and damping ratio of the device.The experiment proves that the frequency of the jetting peak pressure decreases with the length of the self-excited oscillation chamber,increases with the rising of the pump pressure and there is an optimal length of the oscillation chamber corresponding to the jetting surge pressure. lastly, it clearly shows that the device has functions of oscillator and low pass filter and the jetting peak pressure is the highest when the jet dominant frequency close to the natural frequency of the device. The experimental results help to theory analyzing how to improve peak pressure of the self-excited oscillation jet and have some value in engineering.